Image from a FBI and Depart of Homeland Security joint bulletin issued to law enforcement and obtained by AP shows the remains of a black backpack that the FBI says contained one of the bombs that exploded during the Boston Marathon. (AP Photo/FBI)

(AP Photo/ FBI)

WASHINGTON (AP) – An intelligence bulletin issued to law enforcement includes a picture of a mangled pressure cooker and a torn black bag that the FBI says were part of a bomb that exploded during the Boston Marathon.

The bulletin was obtained by The Associated Press.

The FBI says it has evidence that indicates one of the bombs that exploded in the Boston Marathon was contained in a pressure cooker with nails and ball bearings, and it was hidden in a backpack.

The FBI says the other explosive was in a metal container, but there wasn’t enough evidence to indicate that it was a pressure cooker.

It was not known what was used to set off the two explosives that killed three people Monday and injured more than 170 others.

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